Surgical cutting instrument with release mechanism

Abstract

A surgical instrument including a tubular member having a port into which material to be cut is introduced there being a cutter within said tubular member having a cutting edge which is moved by a motor relative to said port to sever the material trapped between the port and the butting edge in which when the cutter movement to produce the severing movement is stopped the motor is rotated in the opposite direction to move the cutter to clear any material trapped between it and the port.

What is claimed is: 
     
       1. A surgical instrument for severing by a shearing action material located between two coacting surfaces comprising an elongated tubular member having a surface defining an opening into which material to be severed is introduced,   a cutter means disposed within said tubular member and having a cutting surface to coact with the surface of said tubular member defining and opening for producing a shearing action of material between said cutting surface and said surface of said tubular member,   means for moving one of said cutting means and tubular member to produce relative motion in a first direction to produce the shearing action of material between said coacting surfaces,   and means responsive to the controlled stopping of relative movement in said first direction causing said moving means to produce relative motion between said cutter means and said surface of said tubular member in a second direction opposite to said first direction for a predetermined amout to clear material trapped therebetween, said cutter means always remaining within said tubular member.   
     
     
       2. An instrument as in claim 1 wherein said moving means moves said cutter means. 
     
     
       3. An instrument as in either of claims 1 or 2 wherein said moving means comprises an electric motor. 
     
     
       4. An instrument as in claim 1 wherein said cutting means is rotatable and said moving means is a bidirectional rotating motor, said motor being rotated in the first direction to produce said shearing action and rotated for a predetermined amount in said second direction to clear the material. 
     
     
       5. An instrument as in claim 4 wherein said motor is coupled to said cutter means to rotate said cutter means relative to said tubular member. 
     
     
       6. An instrument as in claim 1 wherein said responsive means comprises means for sensing the stopping of said moving means and means for applying a signal to said moving means to cause it to operate in a direction to produce relative motion opposite to said first direction. 
     
     
       7. An instrument as in claim 6 wherein said moving means comprises a motor, said responsive means including means for reversing the direction of rotation of said motor. 
     
     
       8. An instrument as in claim 7 wherein said motor is an electric motor, said responsive means including means for sensing a condition when power applied to rotate said motor in a first direction is removed.